Block-signaling system.



J. S. HOLLIZDAY BLOCK SIGNALING SYSTEM. APPLIOATION FILED FEB. 21, 1908.

2 SHEETSSHBBT 1.

INVENTOR Patented Oct. 6, 1908.

CBS

WITNESSES J. S.- HOLL'IDAY. BLOCK SIGNALING SYSTEM.

90,10. I APPLIOATION IILED'I'HBifl, 190s. Patel med Oct. 6 1908'- 2 BBEHTS.8HEET 2.

mam,

UNITED STATES PATENT OFFICE.

& SIGNAL COMPANY, OF SWISSVALE, VANIA.

' TOHN S. HOLLIDAY, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH PENNSYLVANIA, A CORPORATION OF PENNSYL- BIJOCK-SIGNALING SYSTEM.

Specification of Letters Patent.

' Patented Oct. 6,1808.

Application filed February 21, 1908. Serial m. 417,009.

To all whomrtt may concern: V

Be it known that I, JOHN S. HOLLIDAY, of VVilkinsburg, Allegheny county, Pennsylvania, have invented a new and usefulplrm provement in Block-Signaling Systems, of'

' which the following is a full, clear, and exact signaling systems, particularly designed for use on rallways employing electric propulsion, and more particularly to that class of said systems in which the track rails instead of being divided into insulated blocks or sections, are electrically continuous for all currents, both propulsion and signaling.

The object of my invention is to rovide a system of this character which sha be simple in its wiring and generalfarran ement,

, and in which the signal controlling-re ays are of such character as not to be affected by any currents except those which are intended to operate them. a

The precise nature of my invention will be best understood by reference to the accompanying drawings, in which I, have shown diagrammatically one embodiment thereof, and which will now be described, it being premised, however, that various changes may be madethereinby those skilled in the art without departing from my invention as defined in the appended claims.

In these drawings, the numerals 2 and 3 designate the track rails, which are electrically continuous'for all currents both propulsion and slgnahng. Hence, the terms block and section as used herein, are

. not intended to designate separate insulated blocks or sections of the track rails, but are used for convenience to (.lcsignate the portions of the track situated between adjacent signals.

4 and 5 designate the transmission lines for a single-phase signaling current, supplied by an alternator (J.

7 designates the usual thirdrail or overhead conductor for supplying the propulsion current, which may be either a direct current or an alternating current.

8 is a diagrammatic representation of a car or train occupying one of the two blocks or sections shown in the drawing.

9 designates signal-phase transformers for supplying signaling currents from the transmission line to the track rails, the primaries of these transformers being connected across the transmission line and their secondaries being connected across the track rails. These transformers are preferably located at the central portions of the respective blocks. In-

one branch of a conductor 10 leading from the secondary of one transformer to one of the track rails, is a condenser or capacity 11, while in the corresponding conductor leading from the secondary of ,the transformer in the adjacent blocks is an inductance coil ordevice 12. Throughout the system adjacent transformers will in this manner have their secondaries connected to one of the track rails, the one through a condenser or other capacity device, and the adjacent ones through inductances, the inductances and capacities being preferably so adjusted as to give a difference in phase in the current supplied to adjacent blocks of about ninety degrees.

13, 14,15 and ling relays. as employed for each block, and having the contacts 17 of the local signaling circuits controlled thereby in series with each other.

- 18 designates the local circuits, and 19 and 20 the signals which guard the entrances to the res ective blocks and which are controlled the circuits 18.

The re eye 13, 14, 15 and 16 are of the synchrosc'opic tylpe, each having two field wind in s, one of t ese windings consisting of two COIlS 21, which are in series with each other and with a capacity 22 across the transmis- 16 designate signal control sion lines 4 and 5. The otherwinding consists of two coils 23, which are at ninety degrces from the coils 2] and which are also connected in series with each other and with an inductance 24. The rotor element 25 of each relay has a winding 26, which is connected across the track rails 2 and 3.

27 designates the contact controlling arms of the relay's, which are actuated by the rotor elements thereof to control the signal circuits18.

The operation is as follows:-It will be Two of these relays are shown are energized by the current supplied to that block actuate the rotor elements of the relays of that block to hold the signal circuits 18 closed and the signals in clear position, since the currents in coils 23 and the current suplied to the rotor by the transformer of this block reach their maximum at the same time. The currents in the coils 21 being in quadrature with the current in the rotor coils of these relays sup lied by the transformer of that block, it f0 lows that the current from the adjacent transformers which are in phase with the current in coils 21 will have no tendency to close the relays. Therefore, the relays will not be closed by the currents from the adjacent transformers, but will be closed only by the current from the transformer which is located in their own block or section. When the propulsion current employed is a direct current, it will be entirely without effect uponthese relays; and when this current is an alternating current it may have a difierent frequency than the freuency usedin the signaling circuit, so that t ere will be no interference between the si naling and propulsion currents. When a ternating current is used for the propulsion current, I preferably employ three conductors 28, 29 and 30 in the transmission line as shown in Fig. 2, the conductors 28 and 29 being connected to one generator 31, and the conductors 29 and 30 to a second generator 32 of the same frequency, and having its armature mounted on the same shaft as the armature of the generator 31. windings of the relays are connected across the conductors 29 and 30 andthe primaries of the transformers being connected across the conductors 28 and 29. In this manner, there is prevented any tendency of the relays to operate by reason of current set up in the primaries of the transformers by pro ulsion current flowing across the track ralls t rough the secondaries of the transformer and through the rotch' windings of the relays. This is because anyx glclzurrents so generated in the transformer pr' aries flow intothe conductors 28 and 2 9, while the field windings of the relays are connected across the conductors 29 and 30.

Supposin a-train to enter the block which is controlle by the signal 20, as soonas the train has approached within a sufiicient dis-- tance of the relay 16, it will short-circuit that relay, thereby opening the signal circuit 18 The two field and setting the signal at danger. The signalcontrolling contacts 17 of the two relays of each block bein in series, the circuit 18 will remain open so long as a train is in any part of that block, and the train. will therefore be protected by the danger signal behind it. As the train passes into the next block, it retains control of the relay 1.5 until it has gained control of the relay 14, so that itis protected by the signal 20 until the signal 19 has been set at danger.

The coils or windings of the relays can be so adjusted that they will he short-circuited by a train at any desired distance, this depending upon the impedance of the rails, the power factor of the system, and various other factors, which must be determined in advance by the signal engineer in accordance with the usual practice. Owing to the fact, however, that the impedance of the rails will necessarily var somewhat from time to time accordin to the track conditions, more (r less over apping of the blocks occurs which makes it necessary to set the signals back of the entrance to the respective lilocks a sullicient distance to prevent their going to danger in the face of an approaching train;,tlrat is to say, the signal 19 should be set back a sufficient distance behind the entrance to the block which it rotects so that the train will have passed or e passing such signal before the relay 14 is short-circuited by the train.

When there is no train in either block, each relay is receiving current from the transformer of that block, and also slight currents from the transformers of adjacent blocks, these latter currents, however, being in phase with the currents in the coils 21 tend to open to the relays, but are ineffective for that purpose becausethey are much weaker than the currents from the transformer of the same block. When a train in the block protected by the signal 20, for instance, short circuits that block, the current from the transformer between the relays 15 and 16 will tend to assist gravity in holding the relay 14 open.

The coils 21 may, however, be omitted.

The advantages of my invention will be apparent to those skilled in the art. By means of the synchroscopic relays of the character described, the operation of the relays by propulsion or other stray currents, or by currents from other transformers is revented. By using track rails which are e cotrically continuous for all currents, I avoid the necessity for the expensive bonding relays themselves may be of any approved construction, together with the arrangement of the contacts controlled thereby and con-,

trolling the signals.

I claim v 1. "In a block signaling system, track rails which are electrically continuous for all currents, synchroscopic relays each having amovable element connected across the track rails, and means fornnpressmg signaling cur- 2o rents upon'the track rails, said currents being in base in each block with the, current in one fiel dwin ding of the relays for that block; substantially as described.

2. In a block signaling system, track rails which are electrically continuous for all currents, relays having each a coil or winding connected across the-track rails, and two' other windings at an angle to each other, means for sup lying said .windingswith our-- rents which differ in phase by substantially the same angle as the angle between the different windings, and means for impressing upon the track rails currents which differ in piase in adjacent blocks by an angle corre- 85 spondin approximately to the angle of difference etween the two windings of there: lays substantially as described.

' 3. In a block signaling system,track rails which are electrically continuous forall our- 40 rents, transformers'for supplyin signaling current to the track rails, means w ereby the currents supplied by adjacent transformers are of different hase, relays having one .winding connected across the track rails and two othersets of windings at an angle to each other, and means for supplying currents of different phase to the last named windings; substantially as described.

4. In a block signaling system, track'rails whicl are electrically continuous for all ourrents, transformers for im ressing signaling currents upon the track rai s, means for causing the currents impressed upon adjacent v blocks to differ in phase from each other by 5 one set of coils connected across the track rails, and two other windings approximately ninety degrees from each other,"and means for supplying currents to the last named windings differing in phase by approximately substantially ninety degrees, relays having each block at an intermediate portion thereof, means whereby the current supplied by 'adjacent'transformers will differ in phase, a pair of relays for each block having their con-' tacts in series with each other in the signalcontrolling circuit, said relays each having one winding connected across the trackrails,

and two other windings at an angle to each other, and means for supplying currents of different phase to the last named windings;

substantially as described.

6. In a block signaling system, a signal-i controlling relay having three windings, one winding of each relay bein I connected across the track rails and the ot ier two windings being connected to supply conductors, means for supplying the'last named windings with currents of difierent phase, and means for supplying the track rails with currents'of different phase inadjacent blocks thereof;

substantially as described.

7. In a block signaling system, track rails I which are electrically continuous for all currents, relays havin a winding connected across the track rails, and a second winding connected, with supply conductors, and means for im ressing u' on the track rails currents whic are in ase in each block with the current in the fields of the relays of that block, but are in uadrature with the currents in the fields of tne relays of adjacent blocks; substantially as described.

8. In an electric signaling system for use on roads employing alternating propulsion current, a single hase transmission line, signal-controllin re ays, each having one winding connected directly to the transmission line and anotherwindin'g connected to the track rails, and transformers for impressing signaling currents upon the track rails, said transmission line having three conductors, the transformers being connected across two of said conductors and the relay'windings being connected across one of said conductors andthe third conductor; substantially as describedr I 9. In an electric signaling system, a single phase transmission line for the signaling currents, said line having three conductors, two

of which are connected to one generator, and one of these two and the third being connected to a second generator of like frequency, signal -controlling relays having windings connected across two of the said conductors, and' transformers for supplying current to the track railsand having their primaries connected across one of said two conductors and the third conductor; substantially asfdescribed.

10. In an electric-signaling system, track rails which are electrically continuous for all currents, synchrosc oic relays in each block, each relay having its rotor connected to the track and its fields connecter'l to a source of two-phase current, a transformer in each block supplying current to the track, the In testimony whereof, I havehei'eunto set translorinoi' of one block having its primary my hand. I

connected so as to receive one )hnsc of the T o v two-phase current, and the iwi'ainsfoin'lei' of i J0] HOLLIDA} adjacent Mocks having their prii'mnios unn- Vxitnosscs:

nested so as to roccivetho other phase; suh- I. hiumiciuo IJOWA'm),

stzmtiaily as described. DANIEL J. I\'l AR'r1iY. 

